Container



1935 E. H. DOERPINGHAUS 3, ,735

CONTAINER Filed Oct. 26, 1960 5 Sheets-Sheet 1 ATTORNEY Aug. 10, 1965 E. H. DOERPINGHAUS 3,199,735

CONTAINER Filed Oct. 26, 1960 5 Sheets-Sheet 4 ATTORNEY CONTAINER 5 Sheets-Sheet 5 Filed Oct. 26, 1960 FIG. 9

ATTOR/Vf) United States Patent 3,199,735 CQNTAINER Ernst Hans Doerpinghaus, Hamburg, Germany, assignor to Container Patent Co., G.m.b.H., St. Moritz, Switzerland Filed Oct. 26, 1969, Ser. N 65,195

Um'ms priority, application Germany, Feb. 24, 1969,

8 Claims. (Cl. 222-92) The present invention relates to containers in general, and more particularly to containers for the storage and transportation of liquids, of pulverulent and granular materials, as well as of wax-like and other thermoplastic substances which are liquid at elevated temperatures but assume the form of rigid or quasi-rigid bodies at normal or reduced temperatures. Still more particularly, the invention relates to collapsible containers of the above outlined type, i.e. to containers which may assume the form of comparatively small, compact packages when in unfilled condition.

Many types of collapsible and/or foldable containers are already known in the art. Such known containers may be divided into two groups, namely, the one including collapsible containers formed with rigid walls and the other including foldable containers consisting solely of a flexible material, for example, a synthetic plastic substance, which latter may be transformed into extremely small packages when in empty condition but which can normally receive large quantities of liquid or comminuted solid cargo.

The containers of the first group generally consist of rigid, substantially polygonally arranged plates or walls and, in order to protect these walls from direct contact with the cargo, they are provided with internal liners consisting of a flexible synthetic plastic substance. Such liners also cover the joints along which the walls of a collapsible container are connected with each other. A serious drawback of such containers is that they are rather heavy, that they cannot be collapsed into the form of comparatively small packages when free of cargo, that their collapsing or folding mechanism is rather expensive and requires constant maint nance and/or repair, and that the plastic liner is often caught between the movable walls and is destroyed after comparatively short periods of actual use.

The second group of known containers normally assumes the form of flexible plastic bodies whose ends are provided with rounded, substantially wicker basket shaped top and bottom portions. In order to insure that the flexible containers may successfully withstand substantial stresses developing during the lifting of a fully loaded container, while the fully loaded container rests on its bottom portion, and during the evacuation of or loading with cargo, the end zones of the plastic cylinder must be formed with reinforcing beads or other highly resistant reinforcements which add considerably to the overall cost of such containers. Furthermore, a flexible container with a rounded bottom cannot be transported on all types of presently utilized conveyances, for example, fork lift trucks, platform trucks and certain others, which is a decided disadvantage in the handling of such containers. Therefore, all presently known flexible containers must be provided with crane hooks because their handling, excepting by suspension, is either difficult or plain impossible, particularly if they contain large quantities of liquid, pasty or solid cargo.

An important object of my present invention is to provide an improved container which retains all advantageous characteristics of the above described prior containers and which is constructed and assembled in such a way that many or all drawbacks of the known containers are fully avoided in a very simple and economical way.

Another object of the invention is to provide a lowcost container which possesses a number of distinct advantages not attainable with fully flexible or with completely unflexible containers.

A further object of the invention is to provide a foldable container for liquids, pulverulent and hardenable substances which is constructed and assembled in such a way that it may be safely deposited on loose or uneven ground, which may be conveniently transported on all types of conventional conveyances, which may be conveniently loaded and evacuated regardless of the character of its cargo, which may be manufactured in many sizes and shapes by full retention of its advantageous characteristics, and which may be readily adapted to receive materials of widely different physical or chemical characteristics.

An additional object of the instant invention is to provide a container of the above outlined type which is characterized by extremely low tare weight, by a large net weight, by a small stowage volume for transport in empty condition, by great durability against corrosion and many other destructive influences, and which is capable of fully protecting its cargo against external influences, such as water, air, vapors, gases and others.

Still another object of the invention is to provide a container of the above outlined characteristics which may be loaded or unloaded while resting on the ground or while in suspended condition, which may be readily assembled with similar containers to form a stack of small dimensions for convenient storage or transportation in empty condition, whose less resistant component parts are fully concealed and thus protected when the container is free of cargo and is in collapsed condition, and whose interchangeable components may be readily removed and reinserted or replaced without requiring total dismantling of the container.

A concomitant object of the invention is to provide a container of the above described type which may be manufactured at a low cost and may consist of readily available and comparatively cheap materials, which can be readily handled by semiskilled or even by unskilled personnel, which is readily convertible for reception of different materials, which may be constructed in such a way that it will actually assist in rapid evacuation of cargo from its interior, whichthough consisting in part of a flexible material-can readily withstand all such stresses which normally arise in connection with the handling, storage and transportation of liquid, pulverulent, granular, thermoplastic and certain other substances, and which is equally useful for extended as well as for temporary storage of goods.

With the above objects in view, the invention resides in the provision of a collapsible container for granular, powdery, liquid, thermoplastic and even gaseous material which comprises essentially two substantially plate like rigid components and at least one tubular component of flexible material whose ends are permanently or removably secured to the rigid components. The two rigid components preferably assume the form of end plates formed with cargo filling and draining openings, and their dimensions are such that the flexible component may assume a nearly or fully cylindrical or a polygonal shape of constant or of gradually changing cross-sectional area, i.e. though preferably of cylindrical or polygonal shape, the improved container may also assume the form of a truncated cone or of a truncated pyramid.

Another feature of my invention res-ides in the provi sion of a preferably removable liner or inner casing which may be mounted in the interior of the container to prevent direct contact of cargo with the aforementioned componcnts and which may be equipped with or which may simultaneously constitute an ejector meansfor facilitating and for speeding up the evacuation of cargo from the container.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of certain specific embodiments when read in connection with the accompanying drawings, in which:

FIG; 1 is a schematic perspective view of a container embodying one form of my invention, a portion of the flexible component being broken away to reveal the draining or discharge opening in the lower rigid component;

FIG. 1a is a perspective view of a container which, when filled with cargo, assumes the form of a truncated cone;

FIG. 2 is a similar perspective View of a modified container in the form of a hexagonal prism, a portion of the flexible component being broken away;

FIG. 2a illustrates in perspective view a container which assumes the form of a truncated pyramid when at least partially filled with cargo;

'FIG. 3 is an axial section through one-half of a modifled container which is provided with a flexible inner casing, the container being shown in a position ready for the evacuation of cargo from the inner casing;

FIG. 3a is a similar axial section through the other half of the container shown in FIG. 3, the inner casing being shown in partly collapsed condition and free of cargo;

FIG. 4 is an enlarged fragmentary section through the upper rigid component of a containenshowing a diflt'erent manner of sealingly connecting the flexible inner casing to a rigid component;

FIG. 5 is a similar fragmentary section through the upper rigid component of a container and showing still another mode .of sealingly securing the inner casing to a rigid component;

FIG. 6 is an axial section through one-half of a diflerent container which is equipped with a cargo ejecting or evacuating device, the container being shown in fully loaded condition;

FIG. 6a is an axial section .through the other half of the container shown in FIG. 6, the positions of the ejecting device in partly loaded and in fully evacuated condition of the container being respectively illustrated in full and broken lines;

FIG. 7 is an axial section through one-half of a fully loaded container of slightly modified construction embodying composite rigid components and including a different evacuating device which is adapted to lift the cargo to a higher level;

FIG. 7a is an axial section through the other half of the container shown in FIG. 7, the container being illustrated in collapsed condition;

FIG, 8 is an axial section through one-half of a different container in collapsed condition, this container comprising a readily separable flexible component and including special covers for the openings-in the rigid components;

FIG. 9 is a fragmentary top plan view of the cover for the intake or discharge opening as seen in the direction of the arrow M in FIG. 8; and

FIG. 10 is an enlarged fragmentary transverse section taken along the line 1010 of FIG. 3, as seen in the direction of arrows.

Referring now in greater detail to the illustrated embodiments, and first to FIG. 1, there is shown a collapsible container I which comprises two rigid components in the form of substantially disc shaped end plates 1, 2 and a third component in the form of a flexible coat 3. The end plate 1 constitutes the top and the other end plate 2 constitutes the bottom of the container I. These end plates may consist of wood, of a metallic material, or of a synthetic plastic material such as polyethylene, hard polyvinyl chloride, a polyester, a phenolic resin, or the like. Also, each end plate may consist of a mixture of two or more synthetic plastic materials in the above group, and each thereof may be reinforced by glass fibers, felt or textile filaments or in a manner known as sandwich construction. The end late 1 is formed with :1 preferably concentric filling or intake opening 4 which may be sealed by a suitable cover member to be described in connection with FIG. 4 or FIGS. 8, 9, and the other end plate 2 is fromed with a draining or discharge open-ing 5 which is also sealahle by a suitable cover member or cap.

The upper end plate 1 of the container I is connected with a suitable suspending device 6 which comprises a series of flexible elements or cables 8 each of which has its end portions anchored in the material of the rigid end plate 1, for example in a manner as shown in FIG. 8. The flexible elements 8 of the suspending device 6 form two loops which are engaged by a crane hook 7 or another suitable lifting device mounted on a crane, a truck or another lifting and transporting means not shown in the drawings. The lower end plate 2 supports the con tainer I in filled or empty condition on the ground, on a conveyance or on top of another container of similar design.

The flexible coat or mantle 3 consists of one or more plastic layers, and at least one such layer may be reinforced with a textile insert, with longitudinally extending flexible reinforcing strips, and/or with transversely extending reinforcing strips. For example, the reinforcing insert or inserts may consist of plastic-coated Nylon (trademark) fabric or the like. The plastic coating may be polyvinyl chloride, artificial rubber or another preferably low cost synthetic substance. The fabric may be woven in such a way that the warp or woof threads preferably take up the circumferential stresses, i.e. that at least one group of threads extends circumferentially in the flexible mantle. Or course, it is equally possible to reinforce the mantle by non-woven but merely superimposed layers of textile or other threads. By increasing the number of fabric layers, the flexible coat may attain any desired strength such as is necessary in view of the dimensions of the container and in view of the nature and specific weight of the cargo to be stored therein. The plastic coating insures that the cargo is airtightly sealed from the atmosphere while the single or multiple inserts insure a satisfactory resistance to puncturing or ripping, either by impact, by squeezing, crushing, or in any other manner.

The flexible elements 8 may consist of a metallic material, of a synthetic plastic material (e.g. they may as some the form of Nylon cables), or of natural fibers such as hemp or the like.

FIG. la shows a slightly modified container 1' which comprises two rigid circular or oval end plates 1, 2 and a flexible tubular coat 3' whose end portions are connected with the peripheral portions of the end plates. The container 1' is assumed to be at least partially filled with a liquid, pulverulent, granular or thermoplastic cargo which is introduced through the intake opening 4 provided in the upper end plate 1'. It will be noted that the cross-sectional area of the flexible component 3 diminishes gradually in a direction from the bottom end plate 2 toward the top end plate 1. Of course, it is equally possible to utilize the container 1' in inverted position so that the larger-area rigid component 2 constitutes the top plate, particularly since the latter is also provided with at least one opening 5'.

The slightly modified suspending device 6:? for the container 1 comprises a least one flexible element 8a whose end portions are anchored in. the upper end plate 1 at points close to the peripheral portion of this end plate, and at least one flexible element 3b whose end portions E are anchored in the central portion of the upper end plate.

The prismatic container H of FIG. 2 diflers from the containers I and 1 in that its equally dimensioned end plates 101, 132 are of polygonal, i.e. hexagonal contour. These plates are again formed with respective filling and draining openings 164, 165 and are connected to the ends of a tubular coat 1% of flexible material. The suspending device 6 again comprises a series of flexible elements 8 which form loops for suspension on a cable hook 7.

FIG Za shows a container 11' which, when at least partially filled with cargo or when suspended on the crane book 7, assumes the form of a truncated pyramid. It comprises two differently dimensioned rectangular end plates 161, 192' and a flexible coat 163. Again, the cross-sectional area of the coat 103' diminishes gradually in a direction from the end plate N2 toward the end plate lfll'.

As shown in FIGS. 1 and 2, the circumferential length of the flexible coats 3, 1%, respectively equals the peripheral length of the end plates 1, 2, and H91, 132 so that any tensioning forces developing at the connections when the containers are lifted above the ground or when the containers are completely or at least partially filled with liquid, pulverulent or hardened cargo, are uniformly distributed in all zones of the flem'ble coat. This also applies to the containers of FIGS. la and 2a.

An important advantage of the cylindrical, prismatic and truncated containers shown in FIGS. 1, 1a, 2 and 2a i that the flexible tubular coat as well as the end plates may be manufactured and assembled at a very low cost,

that the longitudinal and circumferential stresses are uniformly divided in all zones of the flexible material, and that the dimensions of the collapsed container need not exceed the combined dimensions of its end plates. As is known, the stresses in circumferential direction of the flexible coat develop when the container is at least partly filled with cargo.

It is often preferred to construct the container with circular end plates in the manner as shown in FIG. 1 because such construction facilitates the connection of the flexible coat to the end plates. Common to the constructions of FIGS. 1, la, 2 and 2a is the feature that the reinforcing fabric or fabrics in the flexible coat may be woven in a rectangular pattern, i.e. so that the warp threads extend at right angles to the woof threads. This is possible because the reinforcing layer or layers, particularly in a container or oval end plates, need not extend about concave or irregularly formed parts such as would cause stresses other than in the longitudinal and/ or circumferential direction of the container. In other words, the warp and woof threads may extend in the two directions in which the flexible coat is subjected to maximum stresses, in contrast to the reinforcing threads in tires for automotive vehicle in which the threads are subjected to stresses acting in many directions, i.e. in directions other than at right angles to each other.

Another important advantage of the containers shown in FIGS. 1 to 2a is that the longitudinal stresses may be transmitted to the respective flexible coats by a discshaped or polygonal, i.e. substantially flat upper end plate rather than through reinforced concave or convex top members as in the containers of presently known de sign. Such concave top members must be provided with costly reinforcing devices. The provision of flexible coats with constant or with gradually varying crosssectional area also represents an improvement over containers with substantially pear-shaped flexible coats because a pear-shaped coat requires more material than a cylindrical coat of equal capacity.

It will be readily understood that a substantially prismatic container, i.e., a container with circular or poly onal end plates, may be manufactured at a cost which is much lower than the cost of containers with other than tubular flexible coats and with other than plate like end members because it requires less material and because it can be withstand substantial longitudinal and circumferential stresses which are distributed more evenly than in containers with other than cylindrical or gradually varying tubular coats. Furthermore, and as stated here inabove, the dimensions of the improved container in collapsed condition are smaller than the dimensions of containers with concave or similarly shaped top and bottom members. Also, a container with a plate like bottom is more stable when resting on the ground than a container with an arcuate bottom member.

As stated before, the end plates and the flexible coat of the improved container preferably consist of a readily available material, i.e. wood, metal or synthetic plastic (eg. a polyester reinforced with glass fibers) for the end plates and woven fibres coated with polyvinyl chloride, artificial rubber and the like for the coat. In certain instances, the material of the container could react with certain types of cargo. To avoid such reaction, the cont er may be provided with a flexible inner casor liner whose material will not react with the cargo, and it is preferred to provide a readily interchangeable inner casing which may be of the throw away nature or which may be conveniently clea ed or repaired upon removal from the in e The innor of the outer coat. ner casing may consist of a polyamide, of polyvinyl chloride, polyurethane, silicone, polyester, artiiical rubber, or any other suitable synthetic plastic material which may e formed into sheets and tubes of such dimensions as are required in the improved container. The inner casing may but need not always be reinforced, for example, in the same manner as the outer coat 3 or 193. Thus, the reinforced inner casing may consist of a plasticcoated woven fabric or even of a paper-like material, e.g. crepe paper. if the inner casing consists of paperlilie material, only one or both sides thereof may be coated with a synthetic plastic substance, or alternately, one of its sides may be coated with a first synthetic plastic substance and its other side may be coated with a different second synthetic plastic substance.

A container ill which embodies a flexible inner casing or liner 2d? is shown in FIGS. 3 and 3a. This casing 2%? is received in the flexible outer coat 263 and surrounds the cargo chamber CC. Air which might be entrapped in the intermediate space IS between the inner casing and the outer coat can be released through a suitable exit part 21% which is shown in FIG. 3a and which i is preferably provided in the upper end plate 291. This part may be sealed by a simple plug, by a readily detachable plate Zil, or it may receive a suitable valve of any known design. The openings 2%, 295 in the two end plates may be sealed by plate like or otherwise shaped cover members 2-12, 213, respectively, which are shown in EEG. 3a.

The cargo-receiving inner casing 2%? comprises a tubular and preferably cylindrical portion 259a disposed within the flexible outer coat 203, an upper end portion 253% w.. h is adjacent to the inner side of the upper end plate Ztli, and a lower end portion 28% which is adjacent to the inner side of the lower end plate 292. The end portions 2%917, 2il9c are welded or otherwise bonded to the ends of the cylinder 20%. A tubular extension 2 59.) is concentrically bonded to the upper end portion 2 395) and is sealingly received between the wall of the filling opening and an annular retaining member 214 which is inserted into and which is preferably removably secured in the opening 234. it will be noted that the annular retaining member 214 is formed with a conical outer face whose inclination is the same as or similar to the inclination of the wall surrounding the filling opening 294 so that the upper tubular extension 2991') is compressed into full sealing contact with the adjacent faces of the parts Ztil, 214. The actual filling opening Zilda is formed by the annular retaining member 214 which latter, however, may be removed when the container Ill is used without the inner casing Edi The lower end portion 25% of the inner casing 2% is formed with an elongated tubular extension 2 3% whose outer end may be airtightly sealed by an end wall 2390" which can be welded or otherwise bonded to the lower extension 2690. The diameter of the extension 2990' preierabiy approaches or equals the diameter of the draining opening 265. Since the extension projects into the opening 2&5, this opening is in permanent communication with the interior of the in er casing so that car o may be discharged from the latter whenever the opening 2&5 is exposed.

Of course, it will be readily understood that the inner casing 2&9 may be formed by a process other than welding, e.g. by blowing in a manner known in the production of polyethylene bottles. The advantage of inner casings obtained by a blowing process is that the transition between the cylindrical portion and the end portions 23%, 21190, as well as between the end portions 2091), 26490 and the respective tubular extensions 29922, is of the seamless type.

When the container III is about to be filled, the lower tubular extension 2t9c is folded in the manner as shown in FIG. 3a, and is fully receivable in the draining opening Ztls. The latter is sealed by the cover member 213. However, when it is desired to discharge a cargo from the chamber CC, the cover member 213 is removed so that a liquid or pulverulent cargo fills the lower extension 20% all the way to the end wall 2690'. An important advantage of such construction is that the contents of the container 111 may be evacuated without coming into contact with the outer coat 203 or with the end plates 201, 262. All that is necessary is to form a cut in the lower extension 26% or in the end Wall 2690 at a point distant from the end plate 202. The advantage of this arrangement may be readily understood if one considers that the cargo could be of such nature as to react with the material of the components 2&1, 2G2, 2%3 or that the cargo could contaminate these components. Furthermore, the direction in which the cargo is discharged may be controlled by deflecting the lower extension 41116" from the position shown in FIG. 3. The stream of cargo flowing through the lower extension 2%?0' may be interrupted or reduced by squeezing this extension during the evacuation of material from the cargo chamber CC.

According to a slight modification of my invention which is not illustrated in the drawings, the entire inner casing 26? may consist of a flexible seamless plastic tube which is cut from a prefabricated tubular product of great length and which is thereupon inserted into the outer coat 203 and is squeezed or crimped at both its longitudinal ends so that these ends may fit into the openings 2G4 and 205. The annular retaining member 214 sealingly holds the upper end of the plastic inner casing, and the lower end of this casing is closed in any suitable way prior to the introduction of cargo into the container. Such arrangement further reduces the initial cost of a double-walled container. It is also possible to transform a predetermined length of flexible tubing into the form of an inner casing 209 by passing the tubing through suitable welding and deforming instrumentalities of known design so that the tubing is formed with smaller-diameter tubular extensions at both its longitudinal ends. The lower extension 2090' may be sealed by a length of cord or the like.

Of course, if the container is utilized for the reception of a single type of goods, the inner casing 269 may be permanently installed in the outer coat 203. Furthermore, if the nature of cargo is such that it does not affect the material of the end plates 2G1, 202 but could eventually react with the material of the outer coat 293, the inner casing or liner 209 may assume the form of a tube whose diameter equals or approaches the diameter of the outer her 214A may consist of a rubber like material.

coat 283 and whose ends are secured to the inner sides of the end plates 2% 232. Such inner casing may consist or" an elastic material which should be capable of an expansion to match the diameter of the outercoat. The cargo is then in contact with the tubular inner casing and with the inner sides of the end plates but is sealed from the outer coat 293. In such instances, and particularly if the container is used for reception, transportation and storage of a single type of cargo, the inner casing forms a permanent fourth component of the container. It will be readily understood that, if the cargo does not afiect the material of the inner casing, the latter may be removably inserted in the container and may be exchanged after a series of uses or after predetermined periods of contact with the cargo, i.e. the inner casing is then of the throw-away nature.

PEG. 4 illustrates a slight modification of the construction shown in FEGS. 3 and 3a. Thus, the tubular extension 29% of the inner casing is wrapped about the annular retaining member 214 and has its end portion again sealingly received between the retaining member 214 and the wall of the opening 264 in the upper end plate 2%. In other words, the upper extension 20911 passes outwardly through the actual intake opening 2040 within the retaining member 214 and is thereupon deflected about the outer side of this retaining member to completely enwrap the same and to be sealingly retained in the opening Ztid. This construction has the advantage that the retaining member 214 is out of contact with the cargo and that, therefore, it may consist of any suitable elastic or rigid material regardless of whether or not the material could react with the cargo.

The cover member 212 maintains the retaining member 214 in position within the opening 204 and, as shown in EEG. 4, it may be secured to the outer side of the upper end plate 2:31 by bolts 212a meshing with internally threaded sleeves 291a which are recessed in the upper end plate. Cf course, it will be readily understood that the means for releasably and sealingly locking the cover member 212 to the upper end plate 201 may assume a number of forms, and a preferred form of such connecting means will be described hereinafter in connection with FIGS. 8 and 9.

Another mode of securing the upper tubular extension 23% to the upper end plate 261 is shown in FIG. 5. At its outer side, the end plate 261 is formed with an annular groove 201!) which preferably concentrically surrounds the intake opening 204. The groove 201b receives an annular retaining member 214A which is wrapped into the end portion of the upper tubular extension 20% so that this extension covers the wall of the opening 204 as well as that portion of the outer side of the upper end wall 243]. which extends between the opening 204 and the groove 20117. 'The retaining member 214A is held in the groove 2G1!) by the cover member 212, for example, in the same manner as shown-in FIG. 4. The advantage of the connection between the inner casing and the upper end plate 291 as shown in FIG. 5 is that the retaining member 214A may consist of any sufliciently rigid material because it cannot come into actual contact with the cargo.

The sealing action of the annular retaining members 214, 214A may be improved if they consist of an at least slightly elastic material so that they may be snugly received in the opening 294 or in the groove 20112 and that they are at least slightly deformed when engaged by the cover member 212. FIG. 5 shows that the mem- This insures satisfactory sealing action even if the walls surrounding the retaining member are not finished with great 9 may be collapsed into a small package when not in actual use and also that the container may have a full surfaceto-surface contact with its support during loading, transportation or storage.

The container 1V com-prises two rigid end plates 3M, 3132, an outer coat 393, and an inner casing 389. The ejecting device consists essentially of elastic means which tend to contrast the inner casing 309 inwardly and away from the outer coat 363, preferably in such a way that the inner casing assumes the form of a conical funnel whose smaller-diameter end is adjacent to the opening 395 in the lower end plate 3%. Such elastic means may consist of eX-pansible elastic elements, e.g. bands, cords, strings or strips, which are received to the inner or to the outer side of the inner casing 339 and which constantly tend to impart to the inner casing the shape of a funnel. Alternately, and as shown in FIGS. 6 and 6a, the inner casing itself may consist of an elastic material and is mounted in the container IV in at least slightly stretched condition. Thus, the open upper end portion 399a. of the elastic inner casing 3&9 may be secured to the eripheral portion of the upper end plate 331, and the lower end portion 33% of the inner casing is retained in the dis charge opening 335. When the container IV is empty, the inner casing 339 automatically assumes the position 3t9X which is shown in broken lines in FIG. 6a, i.e. the inner casing assumes the form of a hollow cone or funnel whose larger-diameter end portion 369d is secured to the upper end plate 3% and whose lower end portion is received in the opening 305. Such configuration of the inner casing insures that all traces of cargo are evacuated from the container IV when the lower end portion Ed e is open because the inner casing moves the cargo away from the inner side of the normally horizontal lower end plate 392.

When the container IV is partially filled with say a liquid or pulverulent cargo, the elastic inner casing 3%)? assumes a position which is shown in full lines in FIG. 6:2. It will be noted that the inner casing then resembles an inverted bottle with a convex portion 399 adjacent to its lower end portion 3il9e. This convex portion 3%97" lifts the cargo away from the inner side of the lower end plate 332 and insures rapid evacuation of cargo even if the container IV is only partially filled, e.g. even if the cargo fills it only to the level 315.

When the container IV is loaded with cargo all the Way to the upper end plate 3M (see the cargo level 315:: in FIG. 6), the inner casing 369 expands so that its cylindrical portion 3G9a is adjacent to the inner side of the outer coat 3G3 and that its lower end portion 3690 is adjacent to the inner side of the lower end plate 3E2. The discharge opening 3%5 is sealable by a cover member 313, and a similar cover member may be provided for the intake opening 3-34.

The elasticity of the inner casing 3 39 may be such that this casing expands into the position of FIG. 6 merely by the weight of the cargo, or he cargo may be introduced at such a pressure that the inner casing is forced to expand into full contact with the outer coat 3&3 and with the lower end plate 392. Of course, it will be readily understood that the contracting force of the inner :casing must be suiiiciently strong to assume the full-line or broken-line position of FIG. 6a when the container IV is only partly filled with cargo. During the evacuation of cargo, i.e. when the cargo sinks from the level 315:: to and beyond the level 315, a number of folds is formed in the inner casing 3%? and these fold-s extend from the upper end portion 369d to the lower end portion 352%. Such folds are especially pronounced if the ejecting device consists of elastic cords or strips secured to a nonelastic but flexible inner casing.

Of course, it is not always necessary that the inner casing 309 should contract all the way to the upper end plate 391. For example, satisfactory evacuation of cargo may be insured if the inner casing 369 is secured to the outer coat 363 along a line indicated at 315 in FIG. 6a so that only that portion of the inner casing which is below the line 316 may assume the shape of a funnel during the evacuation of cargo from the container IV. The angle formed by the ejecting device adjacent to the discharge opening 395 must be sufliciently large to insure complete evacuation of cargo by gravity flow. Of course, the connection between the flexible outer coat 393 and the flexible inner casing 3%9 along the line 316 must 'be such that air blown into the intermediate space 18 cannot penetrate into the interior of the inner casing.

According to another feature of my invention, the evacuation of cargo may be facilitated by hydraulic but preferably pneumatic means. For example, and referring to FIG. 3a, the port 219 may be connected to a source of compressed fluid, such as an air compressor, and the fluid then urges the inner casing 209 away from the upper end plate 291 and from the inner side of the outer coat 233 to thereby speed up the evacuation of cargo. It is equally possible to provide one or more air introducing pipes 217 through the lower end plate 2G2 (see FIG. 3), and to connect each pipe 217 with a compressor or blower (not shown) so that the fluid entering between the lower end plate 2&2 and the inner casing 26:9 will cause the latter to assume the shape of a funnel such as is shown at 3=9X in PEG. 6a or any other shape which causes more rapid and complete evacuation of the material contained in the chamber CC. For example, when the cargo consists of cement, the progressive deformation of the inner casing in response to introduction of a gas through one or more valves 218 will be as indicated in FIG. 6 by phantom and broken lines 399', 309', respectively. Each pipe 217 preferably contains a suitable valve 218.

FIGS. 7 and 7a illustrate a container V which is formed with two composite end plates 401, 4%2. The open ends of the tubular outer coat 4133 are assumed to be permanently connected to the peripheral portions of the end plates. The inner casing has been omitted in FIGS. 7 and 7a for the sake of clarity, but it will be understood that the container V may include an inner casing, if desired. The upper end plate 4431 is connected to a suspending device of the type shown in FIG. 1 which includes a series of flexible elements 8 each having its lower end embedded in one or both portions or shells of the composite rigid component dill. In the embodiment of FIGS. 7 and 7a, each flexible element 8 extends through a bore 418 formed in the upper or outer shell 491a of the upper end plate dill and is embedded in a plastic material filling a tapering channel 419 formed in the lower or inner shell 4'31!) of the upper end plate. As mentioned hereinabove, the manner in which the ends of the outer coat 4% are secured to the end plates and the manner in which the flexible elements 8 are anchored in the upper end plate is fully disclosed in my copending application.

The lower end plate 4&2 comprises an outer or lower portion or shell 4532a and an upper or inner portion or shell seal). The configuration of these shells is such that the lower end plate 462 can resist substantial deforming forces despite the fact that its weight is reduced to a minimum. The provision of composite end plates also facilitates the mounting of the flexible outer coat 433. The outer shell 462 a is stiffened by a series of substantially radial reinforcing ribs 429 and by a circumferential reinforcing and suportiug rib 421. The circumferential rib 421 and the inner shell 4432b form a so-called circular box section. The rib 421 tapers in a direction downwardly and away from the shell 4%!) and carries at its annular edge portion a cushioning member 422 of an elastically yieldable synthetic plastic or other material. The cushioning member 422 may be secured to the outer side of or embedded in the material of the circumferential reinforcing rib 421 and comes into actual contact with the ground or with another supporting surface when the container V is not suspended on the flexible elements 8. Thus, the rib 421 actually carries the Weight of the entire container V as well as the weight of the cargo, excepting when the container is lifted above the ground. The periphery of the outer shell 462a along a zone located above the circumferential rib 421 is protected by a tubular or otherwise shaped cushioning member 422a which protects the lower end plate 402 in the event of impact against a hard object.

The central portions of the shells 462a, 4621!) are of conical shape and are received between a pair of retaining sleeves 4-23, 424. A rigid connection between the sleeves 423, 424 and the shells 492a, 4-9212 is preferably established without screws, bolts or the like, for example, by filling the space between the sleeves 423, 424 by a mass f hardenable synthetic plastic filler material 425. The shells 492a, 402b have their central edge portions embedded in the filler material 425 which insures an airtight seal at that point. The discharge opening 495 is defined by the inner retaining sleeve 423. This discharge opening may be sealed by a plug, by a plate, by a cap, or in any other suitable way.

The inner shell 43112 of the upper end plate 491 is stiiiened by substantially radial reinforcin ribs 426 and by a circumferential reinforcing rib 427. The circumferential rib 427 and the inner shell 4311: also form a circular box section. As is clearly shown in FIGS. 7 and 7a, the inner conical wall 427a of the circumferential rib 427 simultaneously forms one wall of the tapering channels 419 which receive the lower ends of the flexible elements 8. The inclination of this inner wall 417:: is preferably such that it is parallel with the flexible elements (see FIG. 7) when the latter are suspended on a hook in the manner as shown in FIG. 1. a

The central portions of the shells dfila, 491k enclose therebetween an annular space 428 which receives an annular stiffening member 429 used to reinforce the wall surrounding the intake opening 4%. As shown, the wall of the opening 494 is of conical shape and its inclination equals or at least approaches the inclination of the peripheral surface on an annular retaining member 414 which is utilized when the container V is equipped with an inner casing of the type shown in FIGS. 3 and 3a. The opening 464 may be sealed by a cover member 412 which is releasably secured to the outer shell 491a in the manner shown in FIG. 4, by clamps, or in any other suitable way. This cover then presses the'annular retaining member 4M- against the wall of the opening 404 to sealingly retain the upper tubular extension of the inner casing in the event that the container V requires an inner casing.

The outer shell 4M0 is formed with a peripheral edge portion 439 of larger diameter whose outer side is preferably provided with an annular cushioning member 431 of an elastically yieldable material. The peripheral edge portion 433 may form an integral part of or it may consist of a metallic or plastic annulus which is either welded or otherwise secured to the main body portion of the shell 4tl1a. As is illustrated in FIG. 7a, the peripheral edge portion 439 overlaps and at least partialry receives the peripheral edge portion of the outer shell 462a and the annular cushioning member 422a when the container V is in collapsed condition. When the collapsed container V assumes the shape of FIG. 7a, it may be rolled on the annular cushioning'member 43?. without damaging the shell 41th: or any other part of the container. The shell itlia may be retained on the shell 4532a merely by friction developing between the inner side of the peripheral edge portion 4-30 and the cushioning member 422a, the latter thus serving to seal the space between the inner shells 401b, 4925; from the surrounding atmosphere when the container V is in collapsed condition. In addition, the cushioning member 422a insures that the edge portion 435) may be moved into the position of FIG. 7a even if the shell 4l1a and/or the shell t-tiZa is not of exactly circular shape, it being assumed that the container V is of a configuration similar to that of the container I shown in FIG. 1. In other words, the elastic cushioning member :22a is considered necessary to insure that the container V may be collapsed without it being necessary that its rigid components be manufactured with utmost precision.

The outer side of the shell itllla is formed with annular platform 432 which serves as a support and abutment means for the circumferential rib of another container placed on top of the container V. As shown, the platform 432 is bounded by an annular bead 432a which prevents lateral movements of two superimposed con tainers with respect to each other. The containers are normally stacked in empty condition (as shown in FIG. 7a), though it is equally possible to place a filled container on top or" another container. The filled container is preferably maintained under a given pressure, he. a gas at a pressure of say 20 cm. water column is introduced into the space 5e at the top of a nearly completely filled container 1V shown in FIG. 6 so that the flexible component or components will retain their shape even if the container is not filled all the way to the inner side of its upper end plate.

Of course, the platform 43?. need not necessarily assume the form of an annular projection but may consist of several, e.g. three isolated protuberances which extend upwardly beyond the outer side of the shell fila.

FIG. 7a shows that the end plates 4G1, may completelyconceal the flexible coat 4%3 when the container V is in collapsed condition. This insures that the flexible coat cannot be damaged during transportation and/or storage and, as mentioned hereinbefore, the cushioning member 422a may. sealingly engage the peripheral edge portion 233 of the outer shell 491a to seal the collapsed flexible coat 4516 from the surrounding atmosphere. A new container V which has been fully tested by the manufacturer is delivered to the user in the form as shown in FIG. 7a, and is preferably lead-sealed after the testing is completed to make sure that no unauthorized persons will tamper with the container before it reaches the user. If desired, the upper shell dilia may be provided with one, two or more pivotably mounted clamping devices 433 which engage the outer wall of the circumferential reinforcing rib 421 when the container V is in collapsed condition. One, two, or more handles 434 may be secured to the circumferential rib 421 to facilitate manual transportation of the collapsed container. For example, the handles 4-34 may consist of short cords or ropes whose ends are embedded in the outer shell 4tl2a in a manner similar to that shown at 419 for the flexible elements 8. Alternately, the handles 434 may serve as means for securing the container V to the ground 435, for example, by being secured to suitable posts embedded in the ground. Of course, the ground 435' may also constitute the platform of a truck or another supporting surface to which the containers are preferably secured during transportation to prevent tilting 'or other displacements.

The container V may be filled or evacuated while suspended on the cables 8 or while resting on the cushioning member 422. Upon removal of the cover member 412, the cargo may be introduced through the intake opening dildo in the annular retaining member 414 or through the opening 494 in the upper end plate 4(51, while the workman removes a plug 435 which normally seals air evacuating Openings formed in the shells 461a, itllb. Of course, the provision of one or more air evacuating openings in the upper end plate is an optional feature of the container since air may also escape through the opening 4- 34 or 43:34: simultaneously with the introduction of cargo through these openings.

If the container V is equipped with an inner casing of the type shown in FIGS. 3 and 3a, the introduction of cargo can be carried out in a more convenient way after expulsion of air from the intermediate space between the outer coat and the inner casing. The plug 436 shea /as is removed and the intake opening 4 34a is connected to a source of compressed air so that the inner casing is caused to assume the outlines of the cargo chamber CC defined by the outer coat 453, by the upper shell 4 31b and by the lower shell 42222. The plug 43:; is then reinserted into its opening which insures that the inner casing will adhere to the inner sides of the parts 4511;, 402b, 4G3 even if the opening 4&3411 is open to atmosphere. The plug 436 may be equipped with a suitable valve so that it may remain permanently installed in the upper end plate 491.

It is not necessary to evacuate air from the inter mediate space between the inner casing and the outer coat before the actual introduction of cargo. Thus, and assuming that the introduction of cargo takes place while the container rests on its lower end plate 4132, the cargo may be introduced at such pressure that the inner casing is caused to assume the shape of the outer coat after the plug 43-5 is removed from its opening in the upper end plate 4%1. Such introduction of cargo at elevated pressures is advisable when the container cannot be suspended during the filling operation. For example, if the interior of the receptacle from which the cargo is transferred into the container V is maintained at a pressure of say cm. water column, the cargo will readily flow into the inner casing by simultaneous expulsion of air from the space between the inner casing and the outer coat. It is often sufficient to introduce the cargo by gravity even if the intermediate space still contains some air.

The evacuation of cargo can be carried out in suspended or in supported position of the container V. When the container is suspended on a crane hook or the like, the cover member for the discharge opening 435 is removed and, in order to prevent a compression of the outer coat 403 under the pressure of atmospheric air, the cover member 412 is removed at the same time so that air may penetrate into the container at the same rate at which the cargo is discharged through the discharge opening 4t35. if the container V is equipped with an inner casing, it is sufiicient to remove the plug 436 so that air may penetrate into the intermediate space between the two flexible components. In such instances, the inner casing will collapse as the cargo is evacuated through the discharge opening 4&5 while the outer coat 403 retains its tubular shape.

If the circumstances are such that the container cannot or should not be suspended during the evacuation of cargo, the discharge opening 405 is placed above the receptacle which is to receive the contents of the container V. If it is desired that the container should not collapse during the evacuation of cargo, air at a pressure slightly higher than atmospheric pressure is pumped into the cargo chamber CC while the cargo flows through the discharge opening 4&5. For example, it is normally sufiicient to introduce air at a pressure of about 10 cm. water column in order to insure that the flexible component 403 will not collapse when the container is free of cargo.

It will be readily understood that the cargo evacuated through the discharge opening 495 may be lifted to a higher level by increasing the pressure in the cargo chamber CC. The height of the level to which the cargo may be lifted depends on the strength of the end plates 401, 462 and particularly on the strength of the flexible outer coat 403. Alternately, the evacuation of cargo to a higher level may be carried out through a pipe 437 which is shown in phantom lines in FIG. 7 and which may be connected to the cover member 412 to extend with its lower end all the Way to or into the proximity of the inner shell 46217. If compressed air is introduced into the cargo chamber CC, the contents of this chamber will be caused to pass upwardly through the pipe 437 to reach a level whose height depends on the pressure prevailing in the chamber CC as well a on the id permissible maximum stresses upon the flexible component or components of the container V. The tube 437 may be replaced by a flexible hose.

As shown in FIG. 7a, the inner retaining sleeve .23 in the lower end plate 4%)2 is preferably formed with internal threads to receive the externally threaded end of a pipe or conduit (not shown) which may replace the pipe 437 of FIG. 7 in the event that it is desired to lift the cargo to a higher level but through the discharge opening 405.

The improved container is equally useful for the transportation and storage of cargo which is rigid at normal or lower-than-normal temperatures and which becomes liquid at elevated temperatures, e.g. parafiines, waxes, greases and like substances. I-leretofore, it was necessary to maintain such cargo at elevated temperatures during transportation or storage to prevent hardening, or it was necessary to heat the container and its contents prior to the evacuation of cargo. Only small modifications are necessary to adapt the container of my invention for the transportation of such thermoplastic substances without it being necessary to heat the cargo prior to its evacuation from the container. Thus, the container may be formed with a separable upper end plate or with a separable lower end plate so that the rigid cargo may be re moved from the underside when the container is in suspended position or from the upper side when the container rests on a support. Assuming that the container is formed with a separable upper end plate, the cargo in the form of a waxy substance may be introduced in liquid state and is then permitted to set so that it forms a rigid cylinder or prism in the interior of the container and that it normally fills the cargo chamber CC. if it is desired to remove the hardened cargo, the upper end plate is separated from the flexible outer coat and eventually from the inner coat, and the entire upper side of the cargo is then exposed for convenient removal from the opened container. For example, and referring to FIGS. 7 and 7a, the container V may be formed in such a way that, instead of providing a permanent connection between the ends of the outer coat 403 and the two end plates 4%, 462, the end plates are secured to the outer coat in a manner as will be presently described in connection with FIG. 8. Thus, the construction of the container V may be such that the lower end portion of the outer coat 493 is separable from the shell 462a and/or 492]; and that the upper end portion of the outer coat 46-3 is separable from the upper shell 451a and/ or 401]). Of course, if the container is without an inner liner, the nature of the separable connection between the flexible coat 4&3 and the end plate 4M and/or 492 must be such that an airtight seal is formed at this point, that the material cannot escape from the cargo chamber CC, and that the connection can stand the weight of cargo in the chamber as well as such elevated pressures in this chamber which become necessary during the evacuation of cargo.

FIG. 8 illustrates a container VI in collapsed condition. This container comprises an upper end plate 501, a lower end plate 502, and a flexible outer coat 503 which latter is partly broken away for the sake of clarity. The upper end plate 501 comprises an outer shell 501a which is formed with a plurality of external substantially radially extending reinforcing ribs 501a", and an inner shell Stiff), and the lower end plate 502 also comprises two shells, namely, an outer shell 562a and an inner shell 50212. The two inner shells 501b, 5152b are of identical configuration which reduces the manufacturing cost of the container VI. The outer shell 592a of the lower end plate 502 is formed with a circumferential reinforcing rib or stiffening means 521 whose conical walls form an annular ridge 521a. The outer side of this ridge is connected with an annular cushioning member 522 of an elastic material, e.g. a synthetic plastic or the like, this cushioning member 522 coming into contact with say the forks of a fork lift truck when the container V1 is moved 15 to a different locale. The shell 502a is further formed with several preferably uniformly spaced supporting legs 538 each of which extends downwardly beyond the circumferential rib 521 and each of which is preferably provided with a cupped cushion 539. The cushions 539 support the container VI on a solid ground but will sink into a softer supporting material so that the container then comes to rest on the annular cushioning member 522. The container is usually formed with three or four legs 533 each of which preferably carries an elastic cushion 539. The elastic cushions 539 insure proper distribution or stresses when the container rests on an uneven support and they also insure that the container will not slide laterally when supported by the forks of a fork lift truck. The forks then engage the cushioning member 522. In addition, the cushions 539 enter into the channels 5610 formed between the radial ribs tl1a" of the upper end plate 501 to prevent relative movement of an upper container with respect to a lower container when two or more containers VI are stacked one atop the other. FIG. 8 indicates schematically and in phontom lines the cushion 539a of an upper container which extends into the radial channel 5010 of the upper side of the end plate 501.

The shells 501a, 501b and 502a, SfiZb may consist of a thermoplastic or duroplastic material, eg a polyester, which is reinforced by felt, by filaments, by glass fibres or the like. As is closely shown in FIG. 8, the shells 561a, Sillb are formed with concentric annular outer edge portions 540, 541, respectively which are welded or otherwise integrally bonded to each other so that these shells form an integral unit. In the illustrated embodiment, the bond between the edge portions 540, 541 consists of a synthetic plastic filler 542. A similar synthetic plastic filler 545 integrally bonds the annular edge portions 543, 54-4 of the respective shells 502a, 5021) to each other, i.e. the shells 502a, 562i; of the lower end plate 502 also constitute an integral unit. The fillers 542, 545, preferably consist of the same material as the shells of the two end plates.

Each of the end plates 501, 592 carries on its peri hery a rigid metallic or plastic retaining ring 546, 547, respectively, whose purpose is to be received in the respective end portion of the flexible coat 563. As is shown in the upper half of FIG. 8, the upper end portion of the coat 503 is bent over itself to form an annular fold which receives the retaining ring 546, and the free annular edge portion 593a of the coat then extends along the outer side of the annular edge portion 540 tobe held in such position by a convoluted metallic wire 548 or by any other suitable clamping means which is preferably wound onto or secured to the edge portion 540 under an initial tension to insure that the upper end of the flexible coat 503 is properly retained in sealing contact with the upper end plate 501 and that this connection can readily withstand all such stresses which normally arise during the handling of a fully loaded container. Since the retaining ring 546 is formed as a rigid body, any stresses transmitted thereto in the event that the convoluted wire 548 should become slightly loose will merely cause the retaining member 546 to bear against the shell and/or against the plastic filler 542, and to thereby by itself hold the upper end of the flexible coat 503 in the illustrated position.

The lower end of the coat 503 is folded about the lower retaining ring 547 and its free annular edge portion 56% is adjacent to the outer side of the annular edge portion 543 to be held in the illustrated position by a pretensioned helically convoluted Wire 549 or another clamping means. It will be noted that the rigid retaining rings 546, 547 are received in comparatively shallow annular notches formed in the outer shells 501a, 502a, respectively, so that these retaining rings cannot slip over the respective fillers 542, 545.

The convoluted wires 548, 549 insure that the connections between the ends of the flexible coat 503 and the end plates 561, 502 remain absolutely airtight. Of course, these convolutions may be replaced by suitable split rings or metallic or plastic material or by any other clamping means which insures an airtight retention of the flexible coat 503.

An annular protecting housing 550 of a rigid synthetic plastic material is provided about the convoluted wire 548 and about the retaining ring 546; the configuration of this housing is such that it is held against axial displacement with respect to the upper end plate 501, for example, by causing the convoluted wire 543 to penetrate into the inner side of the housing 550. A similar annular protecting housing 551 is provided about the convoluted wire 549 and about the lower retaining ring 547. As is clearly shown in FIG. 8, the upper protecting housing 550 is formed with a downwardly extending annular collar 550a which is received in an external annular recess 551:: of the lower protecting housing 551 so that the parts 550, 551 are coupled with each other against lateral displacements when the container V1 is in the collapsed condition of FIG. 8. The upper protecting housing 550 carries a series of outwardly extending headed pins 552 (only one shown in FIG. 8) each of which supports a clamp 553 utilized for releasably securing the housing 550, 551 in the illustrated position. As shown, each clamp 553 is formed with an elongated slot which receives the body of the respective pin so that the clamp is slidable about the adjacent convex portion of the housing 55% between the locking position of FIG. 8 and another position in which its free end is moved away from the lower protecting housing 551. Of course, the shape and the mounting of the clamp or clamps 553 may be changed in a number of ways, e.g., these clamps may be connected directly to the upper end plate Sill and may extend downwardly and beyond the annular member 551, if desired.

The flexible element 8 is connected with the upper end plate 591. For the sake of clarity, I will now shortly describe this connection though it will be understood that its exact construction forms no part of the present invention. The flexible element 8 passes through a cylindrical protecting sleeve 554 which extends through an aperture in the shell 501a and whose lower end is received in the compartment 555 formed between the shells 501a, 5131b of the upper end plate 561. Thus, the sleeve 554 protects the element 8 against excessive wear at the point where the end portion of the element 8 would normally come into contact with the upper end plate. Beyond the lower end of the preferably plastic protecting sleeve 554, the end portion of the flexible element is untwisted, as at 556, to form a group of randomly extending filaments which are ernbeddded in a block 557 consisting of a suitable synthetic plastic material. In this rnanner, the flexible element 8, e.g. a cable consisting of steel wires, of natural fibers or of synthetic fibers, is safely anchored in the upper end plate, preferably in close proximity of the periphery of this end plate. As a rule, the container VI may be formed with two cables 8 each of which has its end portions embedded at diameterically opposed points of the upper end plate with the end portions of one cable disposed at right angles to the end portions of the other cable, i.e. in a manner as shown in FIG. 1 or la. The suspending device consisting of cables 8 may be engaged by a crane hook or another lifting means in a manner which requires no further explanation. To protect the cables 8 against moisture or other external influences, their outer sides may be coated with a layer of suitable protecting material, e.g. a synthetic plastic substance or the like. Alternately, each cable maybe completely impregnated with a suitable plastic substance. If the dimensions of the container are very large or if the container is intended for a heavy cargo, the upper end plate 591 may be connected with four cables 8 instead of with two as shown in FIG. 1. It will be noted that the configuration of the 17 plastic block 557 is such as to insure that the block will not move in the compartment 555, i.e. the outer side of the block 555 hugs the inner side of the annular outer edge portion 541, and the length of this block equals the maximum depth of the compartment 555.

FIG. 8 shows that the block 557 is more distant from the center of the container VI than the supporting leg 538, 539; therefore, if two or more collapsed cn tainers VI are stacked one above the other so that the cushions 53% of the upper container extend into selected channels Sillc of the lower container, the cables 8 may serve as a means for releasably securing the superimposed containers to each other.

The covers 512, 513 for the openings in the respective end plates Sill, &2 are of identical construction. Therefore, I will now describe only the cover 512 for the upper end plate Sill by referring in part to FIG. 8 and in part to FIG. 9. As shown in FIG. 8, the apertured central portions of the shells 591a, Sillb are formed with abutting annular rims Sil'la, Still) the latter of which defines an annular recess for the larger-diameter inner portion 558a of an externally threaded annular coupling member 558 whose externally threaded portion projects outwardly and beyond the outer side of the shell Sula to mesh with a ring nut 559 which clampingly engages the rim 591a to press the rims 501a, 5011; against the inner portion 558a of the coupling member 558. Thus, the parts 558, 559 actually constitute a readily separable coupling wmch clamps the apertured innermost portions of the shells 501a, Still; to each other. In addition, the coupling member 553 defines the actual intake opening 564. This intake opening may be sealed by a bayonet lock assembly comprising an internally threaded member 52ft which is screwed onto the externally threaded portion or hub of the coupling member 558, and a substantially disc-shaped locking or sealing plate 551. As best shown in FIG. 9, the plate 561 is formed with arcuate peripherally arranged tapering cams 562 alternating with arcuate cutouts 563, and the inner side of the internally threaded member 56% is formed with similarly arranged alternating tapering cams 554 and cutouts 565. The cams 562 are insertable into the cutouts 565 so that they may rest on an annular shoulder 558i) formed in the inner wall of the coupling member 553. If the plate 561 is thereupon turned with respect to the member 5150, the cams move between the cams 564 and the shoulder 55812 to thereby frictionally hold the plate 561 in sealing position. The plate 561 is formed with substantially radially arranged external ribs 561a which serve as a handgrip means to facilitate turning of the plate with respect to the member 566. If the operator desires to expose the opening 594, he merely turns the plate 5:31 in the opposite direction to align the same 552 with the cutouts 555 and to align the cams 554 with the complementary cutouts 563, whereupon the plate may be lifted from the opening in the member 560. It will be readily understood that the cams 562, 554 taper circumferentially out in the opposite directions so that they may frictionally engage with each other when the plate 551 is turned and while the cams 562 rest on the shoulder 55%.

The means for preventing accidental separation of the bayonet lock assembly 56%, 561 from the coupling member 558 comprises a radially outwardly extending lug 560a on the member 569 which defines an outwardly facing depression 564312 for a slider member 566. This slider member is mounted on a pin 567 which, in turn, is slidably received in a radially extending elongated closed slot 5-53 formed in the bottom wall of the lug 56%. That end of the pin 567 which projects downwardly and beyond the lug Sada carries a resilient memher in the form of a flat spring 56 which engages with the underside of the lug 565:: to prevent unintentional displacements of the pin 567 in its slot 563. The inner end of the slider member 566 is formed with a transversely extending substantially cylindrical head 570 which extends through a second slot 571 in the bottom wall of the lug 569a and is receivable in one of a series of radially distributed peripheral notches 572 in the member 56% as well as in one of similarly configured peripheral notches 573 in the ring nut 559. Thus, when the slider member 556 assumes the position of FIG. 8, the head 57% extends into one of the notches 5'72 and also into one of the notches 573 to thereby lock the member 556 to the ring nut 559. In this manner, the bayonet lock assembly is safely retained on the upper end plate Sill.

The coupling member 558 defines an annular groove or channel 574 which surrounds the intake opening 5434 and receives a retaining ring 514A whose function is the same as that of the ring 214A shown in FIG. 5. Thus, if the container VI includes an inner casing, the upper end of the inner casing may be folded about to thereby enwrap the retaining ring 514A and is then sealingly received in the annular channel 574 because the ring 514A preferably consists of an elastic material and is sufficiently deformed by the plate 561 to insure that the inner casing is sealingly retained in the end plate 591. The other end of the inner casing may be secured in similar fashion in the lower cover assembly 513.

The compartment 555 between the shells 551a, 5911) as well as the compartment between the shells 562a, 5921) may receive a reinforcing filler of foamed plastic material so as to keep down the weight of the container, a honeycomb paper coated with a stiffening plastic substance, or the like.

I will now describe, only by way of example, the dimensions of a container of the type shown in FIG. 1 as actually manufactured. Thus, the cargo chamber may have a maximum volume of between about 1-3 m? to receive a maximum pay load weighing about 5,000 kg. The weight of the container in empty condition is about 50 kg, its maximum height in loaded condition is between about 1-2.5 m., its height in collapsed condition is about 25 cm., and its diameter approximates 1.2 m. The intake opening may have a diameter of about 10 cm., and the diameter of the discharge opening may be about 10 cm. The flexible elements 8 consist of nylon and the end plates are made of highly durable polyester reinforced with glass fibers.

When the improved container comprises a flexible outer coat and a flexible inner casing, I prefer to provide one or more passages for the flow of air or another gas between the adjacent surfaces of such flexible components. For example, FIG. 10 shows that not only the inner side of the outer coat Zllfi but also the outer side of the inner casing 259 is formed with substantially vertical ribs 203;, 259;, respectively, which define channels or passages 253a, 2590 through which a gas introduced through the pipe 217 may flow to the upper side of the inner casing 299 to thereby assist the evacuation of material from the cargo chamber CC. It will be noted that the configuration and spacing of ribs 203w differs from the configuration and spacing of ribs 29r so that at least a portion of each channel ZliSc, 2090 remains exposed at all times. Of course, the channels between the inner surface of the part 263 and the outer surface of the part 209 may be formed in a IltlIIlbCI of other ways, for example by roughening one of these surfaces or by providing ribs on only one of the parts.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for variout applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A container, particularly for liquid, powdered and like cargo, said container comprising, in combination, a first rigid component constituting the bottom of the container; a second rigid component constituting the top of the container, at least one of said rigid components comprising two shells secured to each other and defining a space between themselves; and at least one flexible tubular coat extending between and having a first and a second tubular end portion respectively connected with said first and second rigid component.

2. A container, particularly for liquid, powdered and like cargo, said container comprising, in combination, an upper end plate and a lower end plate, at least one of said end plates including two circular shells secured to each other and defining a space between themselves, said shells having substantially cylindrical peripheral portions one of which is received in the other thereof; and a flexible tubular coat having tubular upper and lower end portions respectively connected to said upper and lower end plate.

3. A container, particularly for liquid, powdered and like cargo, said container comprising, in combination, an upper end plate; a lower end plate, at least one of said end plates comprising two substantially circular shells connected to each other and defining a space between themselves, said shells having substantially cylindrical peripheral portions one of which surrounds the other thereof; a flexible tubular coat having an upper tubular end portion and a lower tubular end portion; first connecting means for detachably securing one end portion of said flexible coat to said one end plate; and second connecting means for securing the other end portion of said flexible coat to the other end plate.

4. A collapsible container, particularly for liquid, powdered and like cargo, said container comprising, in combination, a rigid upper end plate; a rigid lower end plate, at least one of said end plates comprising two shells connected to each other and defining between themselves an annular space; and a flexible tubular coat extending between and having tubular end portions connected to said end plates.

5. A collapsible container, particularly for liquid, powdered and like cargo, said container comprising, in combination, a pair of end plates of rigid material, at east one of said end plates comprising two substantially circular shells connected to each other and defining a space between themselves, said shells having substantially cylindrical peripheral portions one of which surrounds the other thereof; and a flexible tubular coat having tubular end portions one of which is received between and is permanently connected with the peripheral portions of said shells and the other of which is connected to the other end plate.

6. A collapsible container, particularly for liquid, powdered and like cargo, said container comprising, in combination, a pair of end plates of rigid material, at least one of said end plates comprising two substantially circular shells connected to each other and defining a space between themselves, said shells having substantially cylindrical peripheral portions one of which surrounds the other thereof; and a flexible tubular coat having tubular end portions one of which surrounds and is connected with said one peripheral portion and the other of which is secured to the other end plate.

7. A container, particularly for liquid, powdered and like cargo, said container comprising, in combination, a first rigid component constituting the bottom of the container; a second rigid component constituting the top of the container, at least one of said components comprising two shells connected to each other and defining a space between themselves; and at least one flexible tubular coat extending between and having a first and second tubular end portion respectively connected with said first and second rigid component, one of said rigid components having an outer side formed with a plurality of substantially radially arranged ribs defining between themselves a plurality of radial channels, and the other rigid component having an outer side and formed with a plurality of legs projecting from said last mentioned outer side and spaced in such a way as to be receivable in said channels whereby, when at least two containers are stacked above each other, the legs of one container are received in the channels of the other container to prevent lateral displacements of the containers with respect to each other.

8. A container, particularly for liquid, powdered and like cargo, said container comprising, in combination, a first rigid component constituting the bottom of the container; a second rigid component constituting the top of the container, at least one of said components comprising two shells connected to each other and defining 'a space between themselves; a flexible tubular outer coat extending between and having a first and a second tubular end portion respectively connected with said first and second rigid component; and a flexible tubular inner casing received in and normally contacting at least a portion of said outer coat, said inner casing having an outer surface and said outer coat having an inner surface defining with said outer surface a plurality of small passages to permit the flow of a gas between said inner casing and said outer coat.

References Cited by the Examiner UNITED STATES PATENTS 1,235,550 8/17 Carmody 222- X 2,751,953 6/56 Grimm 1500.5 2,751,954 6/56 Dryg et al l500.5 X 3,001,564 9/61 Hopkins ISO-0.5 3,017,883 1/62 Dickinson 222- X FOREIGN PATENTS 155,096 6/56 Sweden.

RAPHAEL M. LUPO, Primary Examiner.

DOUGLAS J. DRUMMOND, LAVERNE D. GEIGER,

LOUIS J. DEMBO, Examiners. 

1. A CONTAINER, PARTICULARLY FOR LIQUID, POWERED AND LIKE CARGO, SAID CONTAINER COMPRISING, IN COMBINATION, A FIRST RIGID COMPONENT CONSTUTING THE BOTTOM OF THE CONTAINER; A SECOND RIGID COMPONENT CONSTITUTING THE TOP OF THE CONTAINER, AT LEAST ONE OF SAID RIGID COMPONENTS COMPRISING TWO SHELLS SECURED TO EACH OTHER AND DEFINING A SPACE BETWEEN THEMSELVES; AND AT LEAST ONE FLEXIBLE TUBULAR COAT EXTENDING BETWEEN AND HAVING A FIRST AND A 